The major goals of this project are to improve the ability to diagnose mild traumatic brain injury (MTBI) and to test a drug, atorvastatin, which may improve outcome after MTBI. To accomplish these goals, 200 MTBI subjects and 100 orthopedic injury (OI) subjects, for comparison purposes, will be recruited for variety of clinical evaluations and a phase II drug trial. Only the MTBI subjects will participate in the phase II drug trial, and these subjects may choose to participate only in the observational studies, declining the drug trial.